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I had a 350 bored 60 over with 305 HO heads on it that I was going to rebuild until I found out it was already 60 over. I ended up buying an assembled short block, new World Products S/R heads, and a Comp Cams Extreme energy 268 cam. Would I be able to use the push rods from the other engine, in the one I am building?
I would never re-use push rods.You would need to buy a push -rod length tool to find out what size you need to buy.Quote:
Originally posted by richmondb
I had a 350 bored 60 over with 305 HO heads on it that I was going to rebuild until I found out it was already 60 over. I ended up buying an assembled short block, new World Products S/R heads, and a Comp Cams Extreme energy 268 cam. Would I be able to use the push rods from the other engine, in the one I am building?
The rocker ratio (1:5 / 1:6) would be the determining factor, but as eric stated don't use used pushrods. I would call Comp Cams tech line and ask for their advice.
Why are used pushrods a no go?.....I have a set of chromolys that have very few passes on them....I have used used pushrods in the past, thus why I am concerned as to the reasons why you think they shouldnt be re-used. I realize in not using bent ones ...for obvious reasons, but with new lifters and new rockers, a healthy used pushrod will still rotate with the lifter, as long as the pre-load is set correctly when using a hydraulic cam.....please post more on this guys. Anytime i rebuild a motor and do a cam swap, I inspect each pushrod for damage....Ive even taken emery cloth and lightly scored the tips to help them seat with new rockers ans lifters.....I've been lucky and never bent a pushrod, but i also do wise cam selection as well.....
When any of us answer a question on this board, we have an obligation to err on the side of caution. Usually, there is enough talent on the board that any ludicrous answer will be shot down and corrected before the recipient of the info can do any damage to himself or his machinery.Quote:
Originally posted by 81 cabellero
Why are used pushrods a no go?.....I have a set of chromolys that have very few passes on them....I have used used pushrods in the past, thus why I am concerned as to the reasons why you think they shouldnt be re-used. I realize in not using bent ones ...for obvious reasons, but with new lifters and new rockers, a healthy used pushrod will still rotate with the lifter, as long as the pre-load is set correctly when using a hydraulic cam.....please post more on this guys. Anytime i rebuild a motor and do a cam swap, I inspect each pushrod for damage....Ive even taken emery cloth and lightly scored the tips to help them seat with new rockers ans lifters.....I've been lucky and never bent a pushrod, but i also do wise cam selection as well.....
So it is with pushrods. I can appreciate that you inspect and massage yours before re-use and that's o.k., I do the same thing on my own motors. But not everyone does that. Perhaps they don't even think about it if we don't tell them. Most of the guys asking these questions are newbies building their first motor, so if we don't instruct them properly, we could be spending more of their money than is necessary.
A for-instance: What if one or more of the pushrods was subjected to a lack of lubricant and has been overheated, although a visual inspection would perhaps reveal nothing out of the ordinary to the newbie. If, in service, the tip begins to crystalize, the rod will begin introducing shrapnel into the motor, the results of which would be less than acceptable.
Another for-instance: What if the newbie has experienced a cam melt-down and there is shrapnel throughout the motor. You know there is shrapnel and goo inside the pushrods, so if they are re-used without a thorough cleaning, well....you get the idea.
Pushrods are cheap compared to other engine parts, so we ...... again......try to err on the side of caution :)
A quick indicator of pushrod wear is to compare the thickness of the ends by looking at the hole in each end. The thickness, and the wear, is readily seen.